The previous article explained how to create a cluster on Proxmox. However, even though we have created a cluster on Proxmox, if one of the Proxmox servers turns off, the virtual machines on that server will also die and will not automatically switch to another Proxmox server. That’s why we use the high availability feature on Proxmox.
How to use the high availability on Proxmox?
High availability (HA) is a system’s capability to provide services to end users without going down for a specified period. In short, high availability is part of a cluster, but not every cluster is part of high availability. On Proxmox, to use the high availability feature, you must have 3 servers that have created a cluster known as a quorum. In the previous article, I created 2 servers as a cluster. Then I only need to create 1 more server to be included in the cluster to enable the high availability feature at Proxmox. Below is an example image of High Availability at Proxmox, which uses 3 Proxmox servers that have been clustered previously:
To make high availability on proxmox, then on Datacenter – HA click the Add button as shown below:
Then there will be a pop-up, select the virtual machine that will be included in the high availability feature. In this article, I will insert a Virtual1 virtual machine with id 100 on the proxmox1 server machine.
If the Add button on the pop-up is pressed, the Resources column will display as below (if the virtual machine is turned off, then if you click the Add button, the virtual machine will turn on automatically):
Then we do a simulation. First, ping the virtual machine Virtual1 and make sure it can reply. And then we see in the below image the VM is on the proxmox1 server:
After that, try turning off the proxmox1 server and the Virtual1 virtual machine should live to migrate automatically, finally, the virtual machine will be on the proxmox2 server:
And thus, the High Availability feature that you have configured can run well.
If you want to use the High Availability feature in several virtual machines, then you must add these virtual machines in the HA column. And make sure when using this HA feature, you use shared storage such as TrueNAS so that the live migration process can run properly.